1. Field of the Invention
The present invention relates to a safety apparatus for automatically moving an ON/OFF member of a device upon the occurrence of a vibration or shock, such as a seismic disturbance or earthquake. More particularly, the present invention relates to a device operable to automatically close electrical switches or gas valves during seismic disturbances.
2. Description of the Prior Art
Various devices are known in the art for shutting off fuel systems and electrical devices in the event of a seismic disturbance or the like. For example, U.S. Pat. No. 3,994,359 to Smitley discloses a safety shut off fuel system which includes a housing having a first slidable member biased upwardly, but retained in a downward position so long as an inertia ball rests on top of the first member. When the housing is caused to tip, the inertia ball will move away from the first member and allow the first member to move upwardly. This, in turn, frees a second member to be moved by way of a biasing spring into engagement in a fuel passage to cut off the fuel supply. U.S. Pat. No. 4,103,697 to Kiesow discloses a safety sensor device which is operable to automatically shut off the flow of fluids through a passage. The Kiesow device includes a housing having a first member and a second member slidably mounted therein, the first member being biased upwardly, but retained in a downward position by an element connected to a pendulum. When the pendulum is caused to move a predetermined distance due to an earthquake or the like, the first member is moved upwardly, thus allowing a second member to be moved by a spring such that it moves a gate valve into the fluid passage, thereby cutting off flow of the fluid. U.S. Pat. No. 4,475,565 to Keller et al. discloses a magnetically actuable shock responsive unit which includes a housing having a pedestal mounted therein for receiving an inertia ball thereon. Upon occurrence of an earthquake or the like, the inertia ball is caused to move off of the pedestal and press down against a tubular element which, in turn, causes pivoting of a trigger element. Pivoting of the trigger element releases a pivotably mounted valve which is spring biased to a closing position. U.S. Pat. No. 4,546,660 to Bujold discloses an earthquake responsive valve motor which includes a spring biased rotary member adapted to be connected to a gas valve or the like, and a pivotable lever pivotable between a position in which it latches the rotary member against movement toward its spring biased direction, and a releasing position. A pendulum is provided which, upon occurrence of an earthquake or the like, presses upwardly against a portion of the pivotable lever causing the pivotable lever to move to its releasing position. U.S. Pat. No. 4,742,839 to Stock and U.S. Pat. No. 4,429,704 to Jones disclose a vibration activated valve operating mechanism which includes a member attached to a gas valve and spring biased toward a closing position of the gas valve, a member latching the spring biasing member against movement, and a mass member which is operably connected to the latch member, and upon occurrence of an earthquake or the like, causes release of the latch member. U.S. Pat. No. 3,878,858 to Yamada discloses a safety device including a plunger member spring biased toward an extended position, but retained in a retracted position by way of a latch portion of a pivoted lever member. An inertia ball is normally set atop a pedestal but, upon occurrence of an earthquake or the like, is caused to drop off the pedestal and onto one end of the lever member. When this occurs, the lever member is pivoted to a position in which its latch portion no longer latches the plunger. British published specification no. 5132 discloses a device for use in cutting off fuel or energy supplies of various type of vehicles. The device includes a valve member biased toward a closed position but maintained in an open condition by a first member. The first member is biased toward a position on which it allows the valve member to move toward its closed position, but is normally maintained by a pendulum in a position which blocks the closing movement of the valve member. When the pendulum is caused to swing to one side or the other, it allows the first member to move upwardly, thereby allowing the valve member to move to a closed position.